To increase the performance of an engine, in particular an internal combustion engine, these frequently have a charging device, in particular an exhaust gas turbocharger. As a result, exhaust gas of the internal combustion engine is fed to a turbine of the charging device. The charging device, furthermore, comprises a shaft, which couples the turbine to a compressor. Thus, the exhaust gas drives the turbine which through the shaft drives the compressor, which in turn compresses air to be fed to the internal combustion engine, thus increasing the performance of the internal combustion engine. To vary the performance of the charging device and in particular to increase the performance of the charging device at low rotational speeds of the internal combustion engine, the charging device usually has a variable turbine or compressor geometry with guide blades, which depending on position, make available a cross section for the driving exhaust gas. The position of the guide blades in the process is changed through an adjusting device, which as a rule has mechanical limits, which define a minimum set flow and a maximum set flow of the driving exhaust gas. In the process, these limits, in particular the minimum set limit and thus the minimum set flow have a major influence on the performance of the charging device. Disadvantageous with such a charging device is that the mechanical limits change, in particular through wear. Because of this, the performance of the charging device is reduced and/or the adjusting of the guide blades imprecise.